In the operation of a taxicab, the use of a taximeter for determination of the distances traveled with fare paying clients and of the fare paid for this is indispensible. A high percentage of passengers use the taxicab for business travel, which as a rule is subsequently reimbursed, and which therefore require the presentation of a voucher or recept showing the fares. The simplest way of issuing a voucher or receipt is by manual insertion of a fare agreed to with the passenger into a voucher preprinted with certain standard data. Vouchers issued in this fashion use up valuable time and can be manipulated in a random manner especially as the fare data are concerned. In order to facilitate an issuance of vouchers and at the same time create a basis for accurate accounting, a voucher printer is assigned to the taxi microcomputer, which with the help of a simply operable keyboard issues a voucher for the passenger through actuation of a key. The voucher printers presently in use however only prepare vouchers showing the fare determined by the taximeter and transmitted to the printer. The widespread usage of rounding the fare shown on the taximeter upward with the intent to include for the driver a proper "tip" as a surcharge, cannot be transmitted to the printed voucher. Because of this, the use of such printed vouchers is not very popular with taxi drivers. In addition, the passenger has no option to obtain a refund of a "tip" of a normal amount possibly by a fare rounded-off upwards also in tariff areas, where the use of a voucher printer is mandatory, not leastly for protection against inflated vouchers, when settling expense accounts.